The electromagnetic (EM) properties of materials used at elevated temperatures may vary as temperature increases. Accordingly, materials or components that are to be used at elevated temperatures may be tested to determine how the EM properties of those materials or components behave at the elevated temperatures and/or vary with respect to temperature. Guided wave fixtures may be used to test EM properties of samples at elevated temperatures.
Characterization of materials (e.g., determination of EM properties) in a guided wave fixture at elevated temperatures requires that the entire fixture be immersed in a high temperature environment. Over time, the fixtures are subject to multiple temperature excursions (e.g., going from room temperature up to a highest measurement temperature and then back to room temperature). However, because temperature excursions of the fixture itself can affect the measurement values, a typical measurement process includes first measuring the empty fixture at each temperature set point to obtain a baseline measurement, and then repeating the measurements at each set point with the sample loaded in the fixture. Such a process requires two complete temperature cycles, which is time consuming, and also results in additional wear on and/or degradation of the test fixture. Further still, the potential for errors is increased because the baseline and sample data are collected at different times and under potentially different conditions.